I work at an Architecture and Engineering Firm and talked to a guy I know in
out Structural department extensively about getting my 75 and whether it
would be a problem in my house. We discussed slab on grade, and he said
that the slab in my 1902 house was probably 1.5" thick and that it would be
a bad idea to put a 75 on it.

Based on that, I would think that a tank the size of the one in the picture
there would need more than a standard 4" slab on grade. I would want a
footing underneath the slab under the whole tank personally.

He must have a Huge DI or RO unit for topoffs on that thing, and I wonder if
he doesn't have some huge mental health bills as well. J/K, that was my
envy talking.

So, uh ... Anyone care to venture how much it might cost to put something
like this together? =)

I've seen acrylic tanks of this size that are upwards of $5000. No idea
what glass would be. Ongoing costs are going to be a lot too. Guessing
those are 400 watt metal halide lights he has, and there are 8 of them,
that's 3200 watts of lighting which would be $115.20/month at 9 cents per
kilowatt hour and assuming the usual 20% losses in the ballasts. You'd
probably have another $100/month running pumps. I think with a tank this
large Tom's no-heater tank idea would start being very economical too.

And if you want to build this into your house you have two options:
1 - concrete slab on ground floor
2 - concrete slab on steel frame (girders, not truss)

Just tell your contractor to build your fish room like a multilevel parking
structure :-) Seriously though, if you really do build a tank like this you
really should talk to a structural engineer. The tank will be a *lot* of
weight in a small space, and that needs special construction to support it.